The present invention relates to a device for the forced locking of two elements oriented orthogonally to one another.
More in particular, the present invention relates to a device as defined above, wherein the elements oriented orthogonally to one another consist of metal tubular bodies with a quadrangular or polygonal section, which on at least two faces are delimited by a “U” shaped band, equally made of metal. Said tubular bodies comprise, on at least two opposite faces, a plurality of pairs of shaped recesses, suitably spaced from one another, wherein corresponding projections made on the “U” bands abut. A solution of this type, intended for creating modular shelving wherein said tubular bodies are oriented orthogonally to one another, is also known from EP 1,516,559 by the same applicant, and comprises a shaped pin that is inserted crosswise into one of the tubular bodies for fixing the band. Said pin comprises opposite conical zones that make the band tighten both in longitudinal and in cross direction, eliminating a shift originally provided between the holes of one of the tubular bodies and those of the band wherein the pin itself is inserted. A precise and steady coupling is thus obtained over time.
However, it has been found that this type of locking does not exclude the possibility of forming even little clearances over time and due to strains, between the tubular bodies; especially in crosswise direction, at the conical zone close to the coupling pin head, the thrust of a tubular body on the other is less than what occurs at the opposite conical zone, wherein said pin rests on a larger surface. In a bearing structure, a tightening of this kind between two elements that must ensure the load stability may lead to imbalance and give rise to annoying creaks.
In the solution described in EP 1,516,559, moreover, the bottom end of the locking pins screws into a seat formed by a collar projecting outwards, made on each of the bands. As a consequence, the structure formed by the union of multiple tubular bodies orthogonal to one another implies the presence of as many projecting collars as the bands; such collars may constitute hazards points for the people in charge of the structure.